Suppressors for firearms, also known as silencers, generally operate to reduce the audible noise or sharp report of a firing weapon by means of reducing and controlling the energy level of attendant propellant gases. A firearm sound suppressor typically mounts to the end of the muzzle of a firearm and is usually a hollow metal cylinder which has expansion chambers therein and which attaches to the muzzle of a firearm. This type of sound suppressor is readily attached to the end of a firearm barrel and may be used on different firearms of the same caliber.
Firearm sound suppressors work by trapping and delaying the exit of the high pressure muzzle gases from a firearm when the firearm is discharged. Creation of turbulence is one technique used to enhance the trapping of the gases with a subsequent delay in the exit of the gases from a sound suppressor. If a sound suppressor is very effective at trapping and delaying the exit of the gases, this results in a lower sound level coming from the firearm.
Known silencers for firearms can be generally classified into two groups. In one group, the discharge and propellant gases that follow the bullet into the silencer are stored for a short period of time in a plurality of successive chambers which are closed to the outside environment. This produces a controlled expansion of the propellant gases through each chamber, thereby reducing their temperature and pressure.
In a second group, at least a portion of the propellant gases are diverted to exterior coaxial chambers through a plurality of passages between inner and outer walls. Although such arrangements can be complex, these arrangements can provide more capacity to delay and cool the gases, and hence reduce the sound level.
Generally, the techniques include the provision of a series of baffles which control and delay the flow, expansion, and discharge of propellant gases, forcing the propellant gases to pass through various temperature absorbent materials to reduce the temperature and abrupt discharge of propellant gases. The result achieved is a corresponding reduction in the noise produced by the discharged propellant gases.
A firearm suppressor suppresses noise by allowing the rapidly expanding gases from the firing of a cartridge to be diverted or trapped inside a series of chambers. The trapped gas expands and cools, reducing its pressure and velocity before it exits the suppressor. The suppressor chamber may be a single large expansion chamber located at the muzzle end of a firearm to allow the propellant gas to expand considerably and slow before it encounters the baffles therein. Baffles used in sound suppressors are usually circular metal dividers which separate the expansion chamber with each baffle having a hole therethrough to permit passage of gas through the baffle. The aperture in each baffle and the passageway through the sound suppressor are generally slightly larger than the bullet caliber to reduce the risk of a bullet hitting the sides of the housing in the sound suppressor. A sound suppressor housing can become heated to a very high temperature because of the collection of rapidly expanding gases from firing of multiple cartridges, especially in rapid fire weapons.
For typical suppressors, it may become difficult to remove the suppressor from the suppressor housing for cleaning. Tough residue from the discharge gases can build up quickly in and around crevices, creating a bond between the suppressor components which can be difficult to break. Moreover, baffles closer to the muzzle end of the firearm are subjected to greater pressure, contaminants, and heat from the firearm flash during discharge, than baffles located further away from the muzzle end, thereby causing premature wear and failure of the suppressor.
Another disadvantage of current firearm suppressor use is the problem of suppressor instability that results from the use of a threaded connection of the suppressor to the barrel of a firearm. The barrel of a firearm that is designed for attachment of a suppressor is typically provided with a reduced diameter externally threaded section that is of fairly short length. An internally threaded section of a typical suppressor is fairly short, thus causing the threaded connection to have minimal stability due to the typical length of the threaded connection of the suppressor with the firearm barrel.
U.S. Pat. No. 5,136,923 discloses a firearm silencer which includes an outer housing and an interior tube (a central channel) within the housing. The interior tube is spaced from the inside walls of the housing to form an exterior chamber around the interior tube. The interior tube is adapted to receive a projectile discharged from a firearm and extends the entire length of the housing which is attached to a muzzle of a firearm. The interior tube is perforated with a plurality of rows of ports which extend through the wall of the interior tube and discharge into the exterior chamber. The sound suppressing performance of this type of suppressor is considered to be due to the rapid heat exchange between the propellant gases and the surface area of the conductive metal in the suppressor. The efficiency of this type silencer is considered greater on a volume basis for a given projectile clearance than that of baffle silencers. However, because of the limited surface area inherent in this type of design, this type of suppressor is useful only for small fire arms. A sound suppressor of this design having substantially increased surface area for a given volume, for heat dissipation, and that could create greater turbulance of the gases around the length of the interior tube, would be much more effective in suppressing sound and attenuating recoil.
Another problem with prior art suppressors is the large size, especially for suppressors used on rifles which add much overall length to the firearm. Because suppressors for rifles are often long, the length of the rifle is drastically increased, making it inconvenient during use and for storage. For gas impingement rifles and rifles with piston operating systems, such increased length is unavoidable due to the gas tube being positioned directly above the barrel. As such, prior art suppressors are installed on the barrel past the gas block.
It is desirable to provide a suppressor which is conveniently and efficiently assembled to and disassembled from the firearm for convenient cleaning and maintenance. Additionally, it is desirable to provide a suppressor that is exceptionally stable as well as protecting the internal components from the undesirable characteristics of gunpowder residue buildup and fouling. Moreover, it is desirable to provide a suppressor that further suppresses noise and flash discharge, while not unduly increasing the overall length of the firearm. Finally, it is desirable to provide a suppressor that could be integrated with the gas block and gas tube of the firearm.